The shooting happened outside the siblings' home on Aileen Street about 6:40 p.m. Tuesday. The two were outside when they got into an argument, and the younger brother went inside, retrieved a shotgun and came back out, police said.

The brothers began struggling over the weapon and it went off, striking Eugene Chew in the neck, police said. He died at Highland Hospital in Oakland.

Johnny Chew had been held by police on suspicion of murder.

"After a thorough review of all the evidence, the D.A.'s office declined to file charges," said Deputy District Attorney Teresa Drenick, an office spokeswoman. She declined to elaborate.